A method for hardening and mixing piles in aeolian sand geological soft soil

Abstract

The present application relates to cement mixing pile technical field, especially relates to a kind of aeolian sand geology soft soil hardening mixing pile construction method, by being set in the travel recognition unit and torque detection unit on pile machine, the drilling depth and torque change of real-time monitoring drill rod, identify soil layer type and upload information to data acquisition unit, drill rod is made of first drilling rod and second drilling rod, respectively connect driving unit, can be individually controlled rotation direction and speed, to adapt to different soil layer characteristics.In the drilling process, perpendicularity check unit real-time adjustment drill rod perpendicularity, ensure construction accuracy.When guniting operation, according to soil layer type to carry out grading guniting mixing operation, by adjusting drill rod rotation mode and slurry delivery flow, pressure, optimize the mixing effect of slurry and soil layer, solve slurry uneven distribution problem, improve pile strength and composite foundation bearing capacity.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cement mixing pile, and particularly relates to a construction method of aeolian sand geological soft soil hardening mixing pile. BACKGROUND

[0002] Due to the characteristics of low bearing capacity, high compressibility and poor water permeability, the soft soil foundation often needs to be effectively reinforced in engineering construction. Traditional soft soil foundation treatment methods mainly include replacement method, drainage consolidation method and the like, but these methods often have the disadvantages of long construction period, high cost and great influence on the environment.

[0003] The mixing pile machine is a kind of equipment for in-situ mixing and reinforcement of soft soil by using cement, lime and other solidifying agents. Through the special pile machine, the solidifying agent is sprayed into the soft soil foundation, and the solidifying agent is fully mixed with the soft soil through mechanical stirring to cause a series of physical and chemical reactions, so that the soft soil is hardened into cement reinforced soil with integrity, water stability and certain strength.

[0004] In the prior art, during the drilling process of the pile machine, due to uneven geological changes, the drill bit is prone to slipping at the junction of soft and hard soil foundation when encountering the area where the soft and hard soil foundation is staggered, which causes the construction pile machine to tilt and causes a major accident.

[0005] A construction method of a multi-mixing and breaking hardening anti-cracking pile machine is disclosed in Chinese Patent No. 202111118239.5. The mud is subjected to a layered mixing process by multiple mixing methods, making the mud more uniform, preventing local collapse of the pile hole wall, and preventing the formation of cracks that are harmful to the local structure after piling. The structure after piling does not appear to have a diameter reduction phenomenon; the drilling and piling process is monitored by a microcomputer monitoring method, which has certain intelligence and convenience, and can ensure the safety of construction; a telescopic vibration breaking device is installed at the top of the traditional drill bit, which can quickly crush hard rock. The invention makes the mud more uniform, prevents the formation of cracks that are harmful to the local structure after piling, and prevents the local collapse of the pile hole wall; it has certain intelligence and convenience.

[0006] Although the patent similar to the above-mentioned technology is equipped with a telescopic vibration breaking device at the top of the drill bit, which effectively realizes the rapid crushing of hard rock and significantly reduces the risk of tilting of the construction pile machine due to hard soil, but in the special geological environment of aeolian soft soil foundation, the foundation reinforcement operation still faces multiple complex technical challenges.

[0007] The core feature of the aeolian sandy soft soil foundation environment is that it contains a large amount of fine sand and silt. The interaction between these particles results in very low cohesive strength, which makes the soil exhibit significant flow characteristics. When carrying out cement mixing pile construction in such a geological environment, the pile machine is prone to sink, which further causes the drill shaft to deviate, making it difficult to maintain the verticality of the drill shaft, and ultimately affecting the quality control and smooth implementation of the cement mixing pile construction.

[0008] In addition, the geological characteristics of the aeolian sandy area, especially the loose and highly permeable nature of the sand, have a profound impact on the fluidity and permeability of the slurry. Specifically, the slurry tends to spread rapidly and lose in highly permeable sand layers, resulting in a decrease in slurry concentration in this area, forming a so-called "poor slurry zone". Conversely, in dense soil layers, the slurry may accumulate due to blocked permeability, forming a "rich slurry zone". This uneven distribution of slurry further leads to differences in pile strength, affecting the overall bearing capacity stability of the composite foundation, and becomes a key problem that needs to be solved in the reinforcement of aeolian sandy soft soil foundation.

[0009] Therefore, in view of the above problems, it is necessary to provide an aeolian sand geological soft soil hardening mixing pile construction method to solve the above technical problems. SUMMARY

[0010] The purpose of the present application is to provide an aeolian sand geological soft soil hardening mixing pile construction method to solve the technical problems raised in the background art.

[0011] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0012] An aeolian sand geological soft soil hardening mixing pile construction method, the construction method comprising the following steps:

[0013] S1, the pile machine drives to the position, the traction device lowers the drill rod, and the driving unit drives the drill rod to perform the pile drilling process;

[0014] S2, the soil layer where the current drill rod is located is identified by the travel recognition unit and the torque detection unit, and the identified soil layer information is transmitted to the data acquisition unit;

[0015] S3, the verticality of the drill rod is detected and adjusted in real time by the verticality checking unit;

[0016] S4, the drilling depth of the drill rod is judged by the travel recognition unit, if the drilling is in place, go to S5, if the drilling is not in place, return to S2, and continue to perform the drilling operation;

[0017] S5, according to the soil layer information collected by the data acquisition unit, the drill rod performs the up-pumping operation.

[0018] Preferably, the S2 soil layer identification comprises the following steps:

[0019] S201, collecting drilling depth data of the drill rod by a stroke recognition unit, and collecting torque data of the drill rod by a torque detection unit;

[0020] S202, during the drilling of the drill rod, determining whether the torque change of the drill rod exceeds a first threshold value; if the first threshold value is not exceeded, marking the current soil layer as soft soil layer and uploading the soil layer information to the data acquisition unit; if the first threshold value is exceeded, entering S203;

[0021] S203, determining whether the torque change of the drill rod exceeds a second threshold value; if the value exceeds the first threshold value but is less than the second threshold value, marking the current soil layer as hard soil layer and uploading the soil layer information to the data acquisition unit; if the second threshold value is exceeded, marking the current soil layer as gravel layer and uploading the soil layer information to the data acquisition unit.

[0022] Preferably, the S3 verticality verification of the drill rod comprises the following steps:

[0023] S301, constructing a horizontal reference surface by a horizontal verification unit arranged at the bottom of the pile machine;

[0024] S302, determining whether the bottom of the pile machine is in a horizontal state during the drilling of the drill rod, if it is in a horizontal state, maintaining the drilling state, if it is in a non-horizontal state, entering S303;

[0025] S303, determining whether the inclination angle of the bottom surface of the pile machine exceeds a preset value, if the preset value is exceeded, pausing the drilling operation and controlling the traction device to lift the drill rod; if the preset value is not exceeded, leveling the bottom surface of the pile machine by adjusting the supporting foot balancing unit, and returning to S302, and marking the current soil layer of the drill rod as an inclined layer, and uploading the soil layer information to the data acquisition unit.

[0026] Preferably, the S5 lifting and spraying operation comprises the following steps:

[0027] S501, after the drill rod is drilled into position, the traction device lifts the drill rod, and the spraying unit is started to work;

[0028] S502, during the lifting of the drill rod, the soil layer where the drill rod is located is determined and identified according to the stroke recognition unit and the data acquisition unit;

[0029] S503, the spraying unit performs corresponding spraying operation according to the current soil layer category of the drill rod.

[0030] Preferably, if the soil layer where the drill rod currently locates is a soft soil layer, a first-stage jet grouting operation is performed; if the soil layer where the drill rod currently locates is a hard soil layer, a second-stage jet grouting operation is performed; if the soil layer where the drill rod currently locates is a gravel layer, a third-stage jet grouting operation is performed.

[0031] Preferably, if the soil layer where the drill rod currently locates is a deflection layer, a fourth-stage jet grouting operation is performed.

[0032] Preferably, the stroke recognition unit comprises a sensing disc arranged on the traction device, the sensing disc is provided with sensing blocks arranged in an array, and the outer side of the sensing disc is provided with a collection piece for recognizing the sensing blocks; the collection piece obtains the lifting speed and lifting stroke of the drill rod by collecting the number of sensing blocks passing through in a unit time.

[0033] Preferably, the drill rod comprises a first drilling rod and a second drilling rod, the first drilling rod and the second drilling rod are sleeved, and the first drilling rod and the second drilling rod are respectively connected with driving units, so that the rotation of the first drilling rod and the second drilling rod is individually controlled.

[0034] Preferably, the horizontal verification unit comprises a digital electronic level arranged on the pile machine in an array.

[0035] Preferably, the torque detection unit comprises a torque sensor arranged on the output end of the driving unit.

[0036] Technical effects and advantages of the present application:

[0037] 1. The stroke recognition unit and the torque detection unit, combined with the numerical analysis unit of the controller, can monitor the lifting speed, stroke and torque change of the drill rod in real time, so as to accurately judge the type of the soil layer (soft soil layer, hard soil layer, gravel layer, etc.) where the drill rod is located, and upload to the data collection unit, providing a scientific basis for subsequent construction operation, avoiding blind construction, and improving the pertinence and effectiveness of construction.

[0038] 2. According to the collected soil layer information, the rotation direction and speed of the drill rod are adjusted in real time, in the hard soil layer, the drill rod rotates in the same direction to reduce the resistance; in the gravel layer, the drill rod alternately rotates in opposite directions to avoid sticking, effectively improving the penetration ability and construction efficiency of the drill rod, and reducing the risk of equipment damage.

[0039] 3. The verticality verification unit and the horizontal verification unit, combined with the three-dimensional monitoring network of the electronic level, can detect and adjust the verticality of the drill rod in real time. Under the condition of aeolian sand geology, even if the pile machine is deflected, it can be corrected in time through the supporting foot balancing unit, so as to ensure that the drill rod is always in a vertical state, thereby ensuring the construction quality and avoiding the quality problem of pile body caused by deflection.

[0040] 4. The application performs different levels of jet grouting operations according to the soil layer type and the drill rod deflection state; in the gravel layer, high-speed reverse alternating rotation and large flow, high pressure jet grouting are adopted to ensure that the slurry is fully mixed with the gravel; in the hard soil layer, reverse rotation and medium flow, medium pressure jet grouting are adopted to prevent the formation of slurry-poor areas; in the soft soil layer, low-speed co-rotating and medium flow, low pressure jet grouting are adopted to avoid slurry loss. This graded jet grouting method effectively solves the problem of uneven distribution of slurry, improves the uniformity of pile strength, and enhances the overall bearing capacity of the composite foundation.

[0041] 5. The application adopts a three-level response mechanism when the drill rod is deflected, and takes different measures according to the deflection degree; for slight deflection, continuous monitoring is adopted; for moderate deflection, drilling is suspended and the equipment is adjusted; for severe deflection, emergency braking and lifting of the drill rod are adopted. This intelligent response mechanism can effectively avoid equipment damage and construction accidents caused by excessive deflection, and improves the safety and reliability of construction. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1 It is the main flowchart of the construction method of the application;

[0043] Figure 2 It is the flowchart of soil layer identification of the application;

[0044] Figure 3 It is the flowchart of drill rod verticality verification of the application;

[0045] Figure 4 It is the flowchart of lifting jet grouting operation of the application;

[0046] Figure 5 It is the main structure diagram of the pile machine of the application;

[0047] Figure 6 It is the front view of the traction unit of the application;

[0048] Figure 7 It is the left view of the traction unit of the application;

[0049] Figure 8 It is the structure diagram of the drill rod of the application.

[0050] The reference signs are:

[0051] 1. Rack;

[0052] 2. Traction device; 201. Fixed pulley; 202. Traction rope; 203. Winding part;

[0053] 3. Driving part;

[0054] 4. Drill rod; 401. First drilling rod; 402. Second drilling rod;

[0055] 5. The foot balance unit;

[0056] 6. The grouting device; 601, the grouting pump; 602, the grouting pipe;

[0057] 7. The support;

[0058] 8. The stroke recognition unit; 801, the induction disc; 802, the induction block; 803, the acquisition piece. DETAILED DESCRIPTION

[0059] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0060] Embodiment one

[0061] Referring to Figures 5 to 8 shown, the pile machine includes a rack 1, the rack 1 is provided with a foot balance unit 5 on the side, which is used to adjust the horizontal plane of the pile machine; the rack 1 is provided with a support 7 at the end, the support 7 is provided with a drill rod 4 outside, the end of the drill rod 4 is provided with a driving part 3, the inside of the driving part 3 is provided with a driving unit, which is used to drive the drill rod 4 to rotate; the top of the driving part 3 is provided with a traction device 2, which is used to drive the drill rod 4 to perform lifting operation outside the support 7.

[0062] The traction device 2 includes a fixed pulley 201 which is rotatably arranged on the support 7, the outside of the fixed pulley 201 is provided with a traction rope 202, one end of the traction rope 202 is connected with the driving part 3, and the other end is connected with a winding part 203 arranged on the rack 1, the controller controls the rotating direction of the winding part 203 to make the driving part 3 slide outside the support 7.

[0063] The rack 1 is provided with a grouting device 6, the grouting device 6 includes a grouting pump 601, the grouting pump 601 is connected with the drill rod 4 through a grouting pipe 602. The grouting pump 601 makes the slurry sprayed from the bottom of the drill rod 4 through the grouting pipe 602; the above-mentioned related parts belong to the prior art, and will not be described in more detail here.

[0064] Referring to Figures 1 to 8 shown, the present application provides a construction method of aeolian sand geological soft soil hardening mixing pile, the construction method includes the following steps:

[0065] S1, the pile machine drives to the position, the traction device 2 lowers the drill rod 4, and the driving unit drives the drill rod 4 to perform the pile drilling process.

[0066] S2, identify the current soil layer through the stroke recognition unit 8 and the torque detection unit, and transmit the soil layer information to the data acquisition unit.

[0067] The stroke recognition unit 8 comprises a sensing disc 801 arranged on the traction device 2, the sensing disc 801 is provided with an array of sensing blocks 802, and the outer side of the sensing disc 801 is provided with a collection piece for identifying the sensing blocks 802. The lifting speed and lifting stroke of the drill rod 4 can be obtained by collecting the number of sensing blocks 802 passing through the collection piece per unit time.

[0068] When the driving driving part 3 slides outside the support 7, the fixed pulley 201 is pressed to rotate, and the sensing blocks 802 on the sensing disc 801 are driven to rotate. The downhole speed and stroke of the drill rod 4 can be obtained by detecting the number of sensing blocks 802 passing through the collection piece per unit time. Each sensing block 802 has a different signal identifier, and the downhole stroke of the drill rod 4 can be accurately determined by analyzing the signal identifier collected by the collection piece, so as to avoid stroke disorder.

[0069] The torque detection unit comprises a torque sensor arranged on the driving unit.

[0070] The driving unit comprises a driving motor, and the output shaft of the driving motor is in transmission connection with the drill rod 4.

[0071] S201, collect the drilling depth data of the drill rod 4 through the stroke recognition unit 8, and collect the torque data of the drill rod 4 through the torque detection unit.

[0072] S202, during the drilling process of the drill rod 4, it is judged whether the torque change amount of the drill rod 4 exceeds the first threshold value; if the first threshold value is not exceeded, the current soil layer is marked as soft soil layer and the soil layer information is uploaded to the data acquisition unit; if the first threshold value is exceeded, S203 is entered.

[0073] S203, judge whether the torque change amount of the drill rod 4 exceeds the second threshold value; if the value exceeds the first threshold value but is less than the second threshold value, the current soil layer is marked as hard soil layer and the soil layer information is uploaded to the data acquisition unit; if the second threshold value is exceeded, the current soil layer is marked as gravel layer and the soil layer information is uploaded to the data acquisition unit.

[0074] S3, the verticality of the drill rod 4 is detected in real time through the verticality checking unit.

[0075] S4, the drilling depth of the drill rod 4 is judged through the stroke recognition unit 8, if the drilling is in place, S5 is entered, if the drilling is not in place, S2 is returned, and the drilling operation is continued.

[0076] S5, according to the soil layer information collected by the data acquisition unit, the drill rod 4 performs the uphole jet grouting operation.

[0077] The drill rod 4 comprises a first drilling rod 401 and a second drilling rod 402, the first drilling rod 401 and the second drilling rod 402 are sleeved, and the first drilling rod 401 and the second drilling rod 402 are respectively connected with a driving unit, so that the rotation of the first drilling rod 401 and the second drilling rod 402 is controlled separately.

[0078] In use, the pile driver drives to the pile driving position, the supporting legs on the frame 1 are placed down, so that the pile driver is in a horizontal state, then the driving part 3 is controlled to be placed down by the traction device 2, so that the drill rod 4 moves downward, and the driving unit in the driving part 3 is controlled to be started, and the driving unit drives the first drilling rod 401 and the second drilling rod 402 to rotate in opposite directions (for example, the first drilling rod 401 rotates clockwise, and the second drilling rod 402 rotates counterclockwise).

[0079] During the drilling process of the drill rod 4, the torque of the drill rod 4 presents a slow increasing trend with the increase of the drilling depth. The numerical analysis unit of the controller can obtain specific information of the soil layer where the drill rod 4 is currently located by analyzing the data of the torque detection unit and the stroke speed detection unit in real time.

[0080] If the numerical analysis unit detects that the torque change amount of the drill rod 4 in the drilling process does not exceed the first threshold value (that is, the torque growth amount in unit depth is in a stable state), it indicates that the resistance received by the drill rod 4 in the drilling process is small, at this time, the numerical analysis unit marks the current soil layer as a soft soil layer and uploads the soil layer information to the data acquisition unit.

[0081] If the numerical analysis unit detects that the torque change amount of the drill rod 4 in the drilling process exceeds the first threshold value but is less than the second threshold value (that is, the torque growth amount in unit depth is in an exceeding stable state), it indicates that the resistance received by the drill rod 4 in the drilling process is large, at this time, the numerical analysis unit marks the current soil layer as a hard soil layer and uploads the soil layer information to the data acquisition unit; at the same time, the controller controls the first drilling rod 401 and the second drilling rod 402 to rotate in the same direction, reduces the superposition of reverse resistance, and enhances the cooperative penetration ability of the drill rod 4.

[0082] If the numerical analysis unit detects that the torque change amount of the drill rod 4 in the drilling process exceeds the second threshold value (that is, the torque growth amount in unit depth is in an exceeding stable state), it indicates that the resistance received by the drill rod 4 in the drilling process is large, at this time, the numerical analysis unit marks the current soil layer as a gravel layer and uploads the soil layer information to the data acquisition unit; at the same time, the controller controls the first drilling rod 401 and the second drilling rod 402 to alternately rotate in opposite directions through the driving unit, so as to avoid the drill rod 4 from being locked due to gravel jamming.

[0083] In the process of drilling by the drill rod 4, whether the drilling depth of the drill rod 4 is in place is judged by the stroke recognition unit 8, if the drilling is in place, S5 is entered, according to the soil information collected by the data acquisition unit, the drill rod 4 performs the jet grouting operation of lifting. If the drilling is not in place, S2 is returned, and the drilling operation is continued.

[0084] Embodiment two

[0085] Although the above embodiment can identify different soil information in the process of drilling by the drill rod 4, and change the drilling state according to different soil information, but when the mixing pile construction is carried out in the aeolian sandy soft soil environment, the soil flow characteristics are obvious, and the pile machine subsidence problem is easily encountered, further causing the drill shaft to deviate, making it difficult to maintain the vertical state of the drill shaft, and finally affecting the quality control and smooth implementation of the cement mixing pile construction. In view of this, technical improvement is made on the basis of embodiment one, and the improved technical scheme is as follows:

[0086] Referring to Figures 1 to 8 The present application provides a kind of aeolian sand geology soft soil hardening mixing pile construction method, and the construction method comprises the following steps:

[0087] S1, the pile machine travels to place, traction device 2 lowers drill rod 4, and drive unit drives drill rod 4 to execute pile drilling process.

[0088] S2, the soil layer where the current drill rod 4 is located is identified by stroke recognition unit 8 and torque detection unit, and the identified soil information is transmitted to data acquisition unit.

[0089] S3, the verticality of drill rod 4 is detected and adjusted in real time by verticality checking unit.

[0090] S301, a horizontal reference surface is constructed by the horizontal checking unit arranged at the bottom of the pile machine.

[0091] S302, whether the bottom of the pile machine is in a horizontal state during the drilling process of the drill rod 4 is judged, if it is in a horizontal state, the drilling state is maintained, if it is in a non-horizontal state, S303 is entered.

[0092] S303, whether the inclination angle of the bottom surface of the pile machine exceeds the preset value is judged, if it exceeds the preset value, the drilling operation is suspended and the traction device 2 is controlled to lift the drill rod 4, if it does not exceed the preset value, the bottom surface of the pile machine is leveled by adjusting the supporting leg balancing unit 5, and returns to S302, and the current soil layer where the drill rod 4 is located is marked as a deflection layer, and the soil information is uploaded to the data acquisition unit.

[0093] It should be noted that: the supporting leg balancing unit 5 in the embodiment includes a telescopic supporting leg arranged on the side of the rack and driven by hydraulic pressure.

[0094] S4, judge whether the drilling depth of the drill rod 4 is in place by the stroke recognition unit 8, if the drilling is in place, enter S5, if the drilling is not in place, return to S2, and continue to perform the drilling operation.

[0095] S5, according to the soil information collected by the data acquisition unit, the drill rod 4 performs the up-pumping operation.

[0096] The digital electronic level is installed on the drill rod 4 support 7 and the key node of the machine body to form a three-dimensional monitoring network, and can communicate and transmit data to the screen in the cockpit.

[0097] Specifically, the electronic level arranged on the X axis is used to monitor the left and right inclination (along the transverse direction of the drill rod 4); the electronic level arranged on the Y axis is used to monitor the front and rear inclination (along the longitudinal direction of the drill rod 4); and the electronic level arranged on the Z axis is used to monitor the body torsion (optional, used for complex terrain).

[0098] It should be noted that the sensor needs to be embedded in the protective cover to avoid direct impact of sand particles, and the position close to the support leg is used to improve the adjustment relevance.

[0099] The STM32 single-chip microcomputer integrated sensor data is transmitted to the monitoring terminal through the I2C protocol.

[0100] The sampling frequency is set to be greater than or equal to 50 Hz, and the Kalman filter algorithm is combined to eliminate sand vibration noise.

[0101] According to the characteristics of the aeolian sand ground, the offset threshold is set (such as triggering an alarm when the inclination angle is greater than 0.3° or the cumulative offset is greater than 5 cm).

[0102] The three-dimensional inclination model (such as a central dot + offset vector arrow) is displayed in real time on the cockpit display screen to assist the operator to intuitively judge.

[0103] When the pile machine performs the pile construction operation in the aeolian sand ground, if the deflection of the drill rod 4 is monitored, the alarm unit is triggered to alarm (the alarm unit includes an audible and visual alarm).

[0104] The embodiment adopts a three-level response mechanism, specifically:

[0105] When the monitoring terminal detects that the inclination angle of the drill rod 4 is less than or equal to 0.5°, a first level response is triggered, at this time, the drilling state of the drill rod 4 is not changed, the controller continues to monitor the subsequent changes of the inclination angle of the drill rod 4, and the controller has begun to closely track the change trend of the inclination angle although it has not immediately adjusted the state of the support leg. At this time, the hydraulic system inside the telescopic support leg is in standby state, and the pressure sensor (the pressure sensor of the hydraulic system itself) continuously monitors the small pressure fluctuations of the hydraulic oil, and the fluctuation data and the inclination change feedback by the electronic level are mutually verified to make data reserves for the subsequent possible adjustment.

[0106] When the monitoring terminal detects that the inclination angle of the drill rod 4 is between 0.5-1°, a secondary response is triggered, and the controller quickly analyzes the data of the electronic levels in the three-dimensional monitoring network to determine the main direction of the inclination (e.g., left-right inclination along the X-axis or front-back inclination along the Y-axis). Subsequently, the controller sends adjustment instructions to the telescopic legs in the corresponding direction. For example, if the X-axis electronic level shows that the drill rod 4 is inclined to the left, the telescopic leg on the right side of the machine body begins to act, and its hydraulic cylinder, under the precise control of the controller, adjusts the flow and pressure of the hydraulic oil to slowly extend the leg, slightly lifting the right side of the machine body, while the left leg is adjusted accordingly to maintain stable support, to offset the inclination trend.

[0107] During the adjustment process, the controller continuously receives real-time data from the electronic levels and uses the PID control algorithm to dynamically adjust the extension of the telescopic legs, ensuring a smooth and accurate adjustment process. When the electronic levels distributed on the pile machine all return to a stable state, i.e., the inclination angle returns to the allowed range, the controller records the relevant parameters of this adjustment, including the extension of each leg, the adjustment time, etc., and marks the current soil layer as a deviation layer, and uploads this soil layer information to the data acquisition unit for reference for subsequent construction.

[0108] When the monitoring terminal detects that the inclination angle of the drill rod 4 is >1°, a tertiary response is triggered, the traction device stops running and triggers emergency braking, and the controller takes full control of the telescopic legs. At this time, the pile machine needs to be leveled, but the drill rod no longer performs drilling work, and the primary task is to safely and efficiently pull the drill rod out of the pile hole to avoid equipment damage or construction accidents due to increasing inclination.

[0109] The traction device 2, under the instruction of the controller, pulls the drill rod up at a preset slow and uniform speed to avoid hole wall collapse or drill rod jamming caused by rapid extraction.

[0110] While the drill rod is being pulled out, the controller starts the three-dimensional coordinated leveling program: the controller considers all the data of the electronic levels in the three-dimensional monitoring network and adjusts the four telescopic legs in coordination. For example, if the inclination angle mainly exists along the X-axis and Y-axis directions, and the machine body also has a certain degree of torsion (if the Z-axis electronic level has data feedback), the controller will send different adjustment instructions to the four legs, and through precise control of the extension of each leg, the machine body will be reset in three-dimensional space. At the same time, the operator in the cockpit can observe the three-dimensional inclination model and the adjustment state of each leg in real time through the display screen, and can directly understand the adjustment process of the pile machine, and can also manually intervene in the adjustment operation when necessary, to ensure that the pile machine always maintains a safe and stable construction state in the complex wind-blown sand environment.

[0111] Example Three

[0112] Although the above embodiment can adjust the horizontal state of the pile machine by the foot balance unit 5 during the drilling of the drill rod 4, to avoid the problem of deviation of the drill rod 4, in actual application, due to the geological characteristics of the sandy area, when the pile machine is performing the up-pulling grouting operation, the grout is easy to rapidly spread and lose in the strong permeability sand layer, resulting in a decrease in the grout concentration in the region, forming a so-called "poor grout area". On the contrary, in the dense soil layer, the grout may accumulate due to the obstruction of permeation, forming a "rich grout area". This unevenness of grout distribution further leads to the difference in the strength of the pile body, and further affects the overall bearing capacity stability of the composite foundation. In view of this, technical improvement is made on the basis of the second embodiment, and the improved technical scheme is as follows:

[0113] Referring to Figures 1 to 8 The present application provides a kind of aeolian sand geology soft soil hardening mixing pile construction method, construction method includes the following steps:

[0114] S1, pile machine travels to position, traction device 2 lowers drill rod 4, and drive unit drives drill rod 4 to perform pile drilling procedure.

[0115] S2, the soil layer where the current drill rod 4 is located is identified by stroke identification unit 8 and torque detection unit, and the identified soil layer information is transmitted to data acquisition unit.

[0116] S3, the perpendicularity of drill rod 4 is detected and adjusted in real time by perpendicularity checking unit.

[0117] S4, whether the drilling depth of drill rod 4 is in place is judged by stroke identification unit 8, if drilling is in place, enter S5, if not drilling in place, return to S2, and continue to perform drilling operation.

[0118] S5, according to the soil layer information collected by data acquisition unit, drill rod 4 performs up-pulling grouting operation.

[0119] S501, after drill rod 4 drilling is in place, traction device 2 up-pulls drill rod 4, and starts the work of grouting unit.

[0120] S502, during the up-pulling process of drill rod 4, the soil layer where drill rod 4 is located is judged and identified according to stroke identification unit 8 and data acquisition unit.

[0121] S503, grouting unit performs corresponding grouting operation according to the soil layer category where drill rod 4 is currently located.

[0122] If the soil layer where drill rod 4 is currently located is soft soil layer, first-level grouting operation is performed; if the soil layer where drill rod 4 is currently located is hard soil layer, second-level grouting operation is performed; if the soil layer where drill rod 4 is currently located is gravel layer, third-level grouting operation is performed.

[0123] If the current soil layer of the drill rod 4 is a deviated layer, a fourth-stage jet grouting operation is performed.

[0124] During the drilling process of the drill rod 4, the travel identification unit 8 determines whether the drilling depth of the drill rod 4 is in place, if not, the drilling operation is continued. If the drilling is in place, the controller controls the traction device 2 to drive the drill rod 4 to move upward, and at the same time controls the jet grouting pump 601 to start. The jet grouting pump 601 makes the slurry sprayed from the bottom of the drill rod 4 through the grouting pipe 602, and during the upward rotation of the drill rod 4, the slurry is uniformly mixed with the soil layer.

[0125] During the upward rotation of the drill rod 4, the corresponding jet grouting mixing operation is performed according to the soil layer information collected by the data acquisition unit, as shown below:

[0126] In the process of the drill rod 4 performing the jet grouting operation, based on the soil layer characteristic data obtained by the data acquisition unit, the controller accurately controls the jet grouting device 6 and the driving unit to implement a staged jet grouting mixing operation, the specific operation is as follows:

[0127] When the drill rod 4 is in the gravel layer for jet grouting operation, the controller will activate the third-stage jet grouting mixing operation mode. In this mode, the driving unit will drive the first drilling rod 401 and the second drilling rod 402 to rotate in reverse at high speed alternately, and the strong shear force generated by the two can break the gravel, ensuring that the slurry and the gravel are mixed in depth. In order to improve the mixing efficiency, the rotating speed of the second drilling rod 402 is set to be higher than that of the first drilling rod 401, so that the slurry can be more effectively dispersed into the gap between the gravel while breaking the gravel, effectively preventing the formation of a slurry-poor area. At the same time, the slurry delivery pump delivers the slurry at a high flow rate and high pressure to ensure that the pores of the gravel layer are fully filled and the formation of a slurry-poor area is avoided. In addition, the high pressure also helps the slurry to overcome the resistance of the gravel, achieving uniform distribution of the slurry in the entire mixing area.

[0128] When the drill rod 4 is in the hard soil layer for jet grouting operation, the controller will start the second-stage jet grouting mixing operation mode. In this mode, the driving unit controls the first drilling rod 401 and the second drilling rod 402 to rotate in reverse (for example, the first drilling rod 401 rotates clockwise and the second drilling rod 402 rotates counterclockwise), to enhance the shearing action on the soil body and promote the soil body to break and the slurry to mix with the soil body. Since the permeability of the hard soil layer to the slurry is poor, in order to ensure that the mixing space is fully filled and the mixing is uniform, the slurry delivery pump uses a medium flow rate and medium pressure delivery method to cope with the problem of poor permeability of the slurry in the hard soil layer, preventing the formation of a slurry-poor area due to the difficulty of hard soil and slurry to mix fully.

[0129] When the drill rod 4 is in the soft soil layer for jet grouting operation, the controller will start the first-stage jet grouting mixing operation mode. In this mode, the drive unit controls the first drilling rod 401 and the second drilling rod 402 to rotate at a low speed in the same direction. Since the soft soil layer has loose soil, the same direction rotation can make the mixing process more uniform, effectively avoiding the excessive disturbance of the soil layer and the destruction of the soil structure caused by the reverse rotation. This operation can not only ensure that the slurry and the soil are fully mixed, but also prevent the soil from being excessively mixed and the slurry from being lost due to the high rotation speed. At the same time, the slurry delivery pump is in a delivery mode with medium flow and low pressure, which ensures that the slurry is continuously and uniformly filled into the soft soil being mixed during the movement of the drill rod 4, avoiding the formation of a slurry-poor area due to insufficient slurry supply in some areas, or the formation of a slurry-rich area due to excessive slurry accumulation in some areas.

[0130] It should be noted that when the drill rod 4 is in the deflection layer for jet grouting operation, the controller will start the fourth-stage jet grouting mixing operation mode. In this mode, the drive unit controls the first drilling rod 401 and the second drilling rod 402 to rotate at a low speed in the opposite direction alternately, so as to offset the deflection inertia force and keep the drill rod 4 in a relatively stable state of motion in the deflection layer; and prolong the mixing time of the slurry and the soil, and enhance the solidification effect. At the same time, the slurry delivery pump is in a delivery mode with large flow and high pressure, so as to compensate for the uneven diffusion of the slurry caused by the deflection of the drill rod 4. The large flow can ensure that the slurry can quickly and fully fill the voids in the deflection layer, and the high pressure can enhance the permeability of the slurry, so that the slurry can better combine with the soil. At the same time, pulse grouting (intermittent injection) is adopted to promote the penetration of the slurry by pressure fluctuation. Pulse grouting can form a pressure gradient in the slurry in the soil, so that the slurry can more easily penetrate into the small pores of the soil.

[0131] It should be noted that the adjustment of the flow and the pressure is realized by the frequency converter and the proportional valve. The controller adjusts the output frequency of the frequency converter and the opening of the proportional valve in real time according to the deflection degree of the drill rod 4 and the actual situation of the soil layer, so as to accurately control the flow and the pressure of the slurry.

[0132] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can make equivalent replacement or change according to the technical solution and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A method for constructing hardened mixing piles in aeolian sandy soil geology, characterized in that: The construction method includes the following steps: S1. The pile driver travels to the designated position, the traction device lowers the drill rod, and the drive unit drives the drill rod to perform the pile drilling process. S2. The soil layer where the drill rod is located is identified by the stroke identification unit and the torque detection unit, and the identified soil layer information is transmitted to the data acquisition unit. S201. The drilling depth data of the drill pipe is collected through the stroke recognition unit, and the torque data of the drill pipe is collected through the torque detection unit. S202. During the drilling process, determine whether the change in the drill rod torque exceeds the first threshold. If it does not exceed the first threshold, mark the current soil layer as a soft soil layer and upload the soil layer information to the data acquisition unit. If it exceeds the first threshold, proceed to S203. S203. Determine whether the change in drill rod torque exceeds the second threshold. If the value exceeds the first threshold but is less than the second threshold, mark the current soil layer as a hard soil layer and upload the soil layer information to the data acquisition unit. If it exceeds the second threshold, mark the current soil layer as a gravel layer and upload the soil layer information to the data acquisition unit. S3. The verticality of the drill pipe is detected and adjusted in real time through the verticality verification unit; S301. A horizontal reference surface is constructed by setting a horizontal verification unit at the bottom of the pile driver; S302. Determine whether the bottom of the pile driver is horizontal during the drilling process. If it is horizontal, continue drilling. If it is not horizontal, proceed to S303. S303. Determine whether the tilt angle of the bottom surface of the pile driver exceeds the preset value. If it exceeds the preset value, suspend the drilling operation and control the traction device to lift the drill rod. If it does not exceed the preset value, adjust the bottom surface of the pile driver by adjusting the support balance unit and return to S302. At the same time, mark the soil layer where the drill rod is currently located as the tilt layer and upload the soil layer information to the data acquisition unit. S4. The stroke recognition unit determines whether the drill pipe has reached the required drilling depth. If the drilling has reached the required depth, proceed to S5. If the drilling has not reached the required depth, return to S2 and continue drilling operations. S5. Based on the soil layer information collected by the data acquisition unit, the drill rod performs the corresponding upward grouting operation; S501. After the drill rod is drilled into place, the traction device lifts the drill rod and the shotcrete unit starts working at the same time. S502. During the drill rod lifting process, the soil layer where the drill rod is located is judged and identified based on the stroke identification unit and the data acquisition unit. S503. The shotcrete unit performs the corresponding shotcrete operation according to the soil layer type where the drill rod is currently located. If the soil layer where the drill rod is currently located is soft soil, then perform a level 1 grouting operation; if the soil layer where the drill rod is currently located is hard soil, then perform a level 2 grouting operation; if the soil layer where the drill rod is currently located is gravel, then perform a level 3 grouting operation; if the soil layer where the drill rod is currently located is an inclined layer, then perform a level 4 grouting operation. The drill rod includes a first drill rod and a second drill rod, which are sleeved together. The first drill rod and the second drill rod are respectively connected to a drive unit so that the rotation of the first drill rod and the second drill rod can be controlled independently. During the drilling and grouting process, the corresponding grouting and mixing operation is performed based on the soil layer information collected by the data acquisition unit, as shown below: During the shotcreting operation on the drill pipe, based on the soil characteristic data acquired by the data acquisition unit, the controller will precisely adjust the shotcreting device and drive unit to implement a staged shotcreting mixed operation. The specific operation is as follows: When the drill rod is in the soft soil layer for grouting, the drive unit controls the first and second drill rods to rotate in the same direction at a low speed. Because the soft soil layer is loose, rotating in the same direction can make the mixing process more uniform. At the same time, the grout delivery pump uses a medium flow rate and low pressure to ensure that the grout is continuously and evenly filled into the soft soil being mixed as the drill rod moves upward. When the drill rod is in hard soil layer for grouting operation, the drive unit controls the first drill rod and the second drill rod to rotate in opposite directions to enhance the shearing effect on the soil, promote soil breaking and full mixing of grout and soil; the grout delivery pump adopts medium flow and medium pressure delivery mode to deal with the problem of poor grout permeability in hard soil layer; When the drill rod is performing shotcreting in the deviated layer, the drive unit controls the first and second drill rods to rotate alternately in opposite directions at low speeds to counteract the inertial force of the deviated layer and keep the drill rod in a relatively stable motion state in the deviated layer. At the same time, the slurry delivery pump uses a high-flow-rate and high-pressure delivery method to compensate for the uneven slurry diffusion caused by the deviated drill rod. When the drill rod is in the gravel layer for shotcreting, the drive unit drives the first and second drill rods to rotate alternately in opposite directions at high speed. The strong shear force generated by the two rods breaks the gravel, ensuring that the slurry and gravel are deeply mixed. The rotation speed of the second drill rod is set to be higher than that of the first drill rod, so that while breaking the gravel, the slurry is more effectively dispersed into the gaps between the gravel, effectively preventing the formation of a slurry-poor zone. The slurry delivery pump delivers the slurry at a high flow rate and high pressure, ensuring that the pores of the gravel layer are fully filled and avoiding the formation of a slurry-poor zone.

2. The construction method for hardening mixing piles in aeolian sandy soil geology according to claim 1, characterized in that, The stroke recognition unit includes a sensor disk installed on the traction device. The sensor disk has an array of sensor blocks distributed on it. A data acquisition device for recognizing the sensor blocks is provided on the outside of the sensor disk. The data acquisition device obtains the lifting speed and lifting stroke of the drill pipe by collecting the number of sensor blocks passing through per unit time.

3. The construction method for hardening mixing piles in aeolian sandy soil geology according to claim 1, characterized in that, The level verification unit includes digital electronic levels arrayed on the pile driver.

4. The construction method for hardening mixing piles in aeolian sandy soil geology according to claim 1, characterized in that, The torque detection unit includes a torque sensor disposed on the output end of the drive unit.

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